Automatic seat belt release system

ABSTRACT

The automatic seat belt release system will energize solenoids mounted on the female portion of the seat belt latches. The solenoids will push the release button on the female seat belt latch via the solenoid and release the belt automatically. In addition, the individual seat belt can manually opened by the children in each seat in the school bus for normal day to day operation.

The system has two separate control paths for seat belt automatic release. (See FIG. 1). Both paths will receive the 12 volt D.C. from the level switch control (LSW), via the level relay (LR). The level switch control will prevent the solenoids from being energized if the bus is upside down. The level relay contacts (LRC1) will furnish power to the inertia control mechanism (IS) for automatic switching due to an accident. The inertia controls (ISC) will energize the time control (TC) to make sure all solenoids have sufficient time to energize and release the seat belt latches. The voltage will be switched through the time control contact (TCC). The time control contact (TCC) will switch through the 12VDC directly to the solenoids used to push the release mechanism on the female connector on the seat belt.

The system also has a driver enunciated section, the level switch also furnishes voltage via the level contacts (LRC2) to the driver switch. The driver can manually energize the solenoids from a switch located in the dashboard. Thus opening the seat belt latches.

The solenoids (FIGS. 2+3) will be attached to the female latch. Assembly via flanges (FIG. 3) that are fastened to the latches on screws or adhesive depending on the type of female brackets. The design notes of the solenoids (S) are as follows.

One of the problems we encountered when trying to incorporate a seat belt non-latched system (application Ser. No. 11/700,712) was the problem of seat belts on school buses. The system will do the job with no problems, except when a small child could possibly panic after an accident and not be able to open their seat belt. This system would automatically release the seat belts via the driver or timed release through a control center. The detail operations will be covered in the latter of this patent application.

1. Voltage 12 VDC

2. Duty Cycle: Continuous

3. Stroke: mm/inches 0.75 inches

4. Dielectric strength of coil: 1000 VRMS

5. Plunger: free floating push type

6. Solenoid shall develop

-   -   a. 6 lb net force     -   b. 0.75 mm/inches stroke     -   c. 40 ma amps (SIM 12 VDC at +20 degrees Celsius

7. Detail specification drawing (FIG. 4)

The seat belt release latching system is an electronic system that will release seat belts on motor coaches (school buses) via driver intervention or automatic release initiated by an inertia device and electronic timer. The 12VDC is furnished by the load side of the ignition switch to power the system. An in-line fuse will protect the system. (F). 

1) the driver will energize the system via a mechanical hold (push-on, push off) switch. The load side of the switch will furnish the voltage to energize the individuals solenoids. The solenoids are located on the females receptor (See drawing on FIGS. 1+2). 2) The system will also be energized via an inertia assembly switch thru an electronic timer to energize the solenoids after a suitable time to release the seat belts after an accident. The system will also incorporate a level sensor to prohibit the system from energizing the solenoids if the bus is not in an upright position. The level sensor will control both automatic and manual driver activation to prevent opening the seat belts if the school bus is up side down. 